#!/usr/bin/perl
# 
#  Exercise 4.5
# 
# Sometimes information flows from RNA to DNA. Write a program to reverse tran-
# scribe RNA to DNA.
#
# Answer to Exercise 4.5

# The RNA
$DNA = 'ACGGGAGGACGGGAAAAUUACUACGGCAUUAGC';

# Print the RNA onto the screen
print "Here is the starting RNA:\n\n";

print "$RNA\n\n";

# Reverse transcribe the RNA to DNA by substituting all U's with T's.
$DNA = $RNA;

$DNA =~ s/U/T/g;

# Print the DNA onto the screen
print "Here is the result of reverse transcribing the RNA to DNA:\n\n";

print "$DNA\n";

# Exit the program.
exit;
